The present invention relates to a reactor for reducing the contents of nitrogen oxides and sulphur oxides in combustion gases, which reactor comprises a post-combustion chamber to be connected together with or after a combustion chamber.
A major problem in the combustion of liquid and solid fuels is the content of sulphur oxides and nitrogen oxides present in the flue gases. Thus, many attempts have been made to reduce this oxide content, both by flue gas cleaning and by catalytic treatment of the exhaust gases.
The invention is based on the insight that it is possible to reduce the content of nitrogen oxides and sulphur oxides to a considerable extent if it is ensured that suitable oxidation and temperature conditions prevail in the passageway between the combustion chamber and the chimney.
Swedish Patent 7804761-0 (SE-B-413,158) discloses an apparatus for the combustion of a mixture of gaseous or particulate, combustible material and combustion air. This apparatus is used for combusting various gaseous or particulate materials containing carbon or carbon compounds, in such a complete manner that the combustion gases emitted are practically free from soot, carbon monoxide and hydrocarbon residues. It is, however, not stated in the patent specification that the apparatus can be used for reducing the contents of nitrogen oxides and sulphur oxides in combustion gases.
U.S. Pat. No. 4,481,889 discloses a method for afterburning flue gases by conducting the impure gases through a burner in an afterburner in which the exhaust gases, by being positively mixed with a combustion gas, are subjected to complete combustion. In this process, combustible gases are thus supplied to bring about afterburning of the flue gases.
DE-A-3,014,590 discloses a pre-combustion chamber for an oil- or gas-fired, fan-supported burner. This pre-combustion chamber serves to shape the generated flame and to retard it before entering the combustion chamber. This apparatus thus serves as an intermediary between the burner and the combustion chamber, whereas not as a reactor for reducing the contents of nitrogen oxides and sulphur oxides in combustion gases.